Diabetes is a disease caused by multiple factors and characterized by hyperglycemia which may be associated with increased and premature mortality due to an increased risk for microvascular and macrovascular diseases such as nephropathy, neuropathy, retinopathy, atherosclerosis, polycystic ovary syndrome (PCOS), hypertension, ischemia, stroke, and heart disease. Type I diabetes (IDDM) results from genetic deficiency of insulin, the hormone regulating glucose metabolism. Type II diabetes is known as non-insulin dependent diabetes mellitus (NIDDM), and is due to a profound resistance to insulin regulatory effect on glucose and lipid metabolism in the main insulin-sensitive tissues, i.e., muscle, liver and adipose tissue. This insulin resistance or reduced insulin sensitivity results in insufficient insulin activation of glucose uptake, oxidation and storage in muscle and inadequate insulin repression of lipolysis in adipose tissue as well as glucose production and secretion in liver. Many Type II diabetics are also obese, and obesity is believed to cause and/or exacerbate many health and social problems such as coronary heart disease, stroke, obstructive sleep apnoea, gout, hyperlipidemia, osteoarthritis, reduced fertility, and impaired psychosocial function.
A class of compounds, thiazolidinediones (glitazones), have been suggested to be capable of ameliorating many symptoms of NIDDM by binding to the peroxisome proliferator activated receptor (PPAR) family of receptors. They increase insulin sensitivity in muscle, liver and adipose tissue in several animal models of NIDDM resulting in correction of the elevated plasma levels of glucose, triglycerides and nonesterified free fatty acids without any occurrence of hypoglycemia. However, undesirable effects have occurred in animal and/or human studies including cardiac hypertrophy, hemadilution and liver toxicity.
Most PPARγ agonists currently in development have thiazolidinedione ring as their common chemical structure. PPARγ agonists have been demonstrated to be extremely useful for the treatment of NIDDM and other disorders involving insulin resistance. Recently, troglitazone, rosiglitazone, and pioglitazone have been approved for treatment of type II diabetes. There is also indication that benzimidazole-containing thiazolidinedione derivatives may be used to treat irritable bowel disorder (IBD), inflammation, and cataract (JP 10195057).
JP 09012576 (Yoshitake et al.) discloses benzothiazine derivatives stated as useful therapeutic agents for circulatory system disease and glaucoma.
JP 09012575 (Hiroaki et al.) discloses benzoxazine and benzothiazine derivatives stated to be useful as prophylactic drugs and/or therapeutic drugs in hyperlipemia, hyperglycemia, obesity, diseases attributable to sugar tolerance insufficiency, hypertension, osteoporosis, cachexia, and complications of diabetes such as retinopathy, nephrosis, neuropathy, cataract, coronary artery disease and arteriosclerosis.
WO 99/20614 (Lohray et al.) discloses β-aryl-α-oxysubstituted alkylcarboxylic acids stated as antiobesity and hypocholesterolemic compounds which may have agonist activity against PPARα and/or PPARγ, and optionally inhibit HMG CoA reductase.
WO 97/17333 (Frechette et al.) and U.S. Pat. Nos. 5,696,117 and 5,854,242 to Frechette et al. disclose benzoxazine and pyrido-oxazine compounds having a moiety of a fused phenyl or fused pyridyl, pharmaceutical compositions containing the compounds, and methods for their production and their use in treating bacterial infections.
U.S. Pat. No. 5,859,051 to Adams et al. discloses the following acetylphenols, wherein substituents are as described in the reference, which are stated to be useful as antiobesity and antidiabetic compounds without the thiazolidinedione moiety.
WO 99/38845 (De La Brouse-Elwood et al.) discloses the following compounds, wherein substituents are as described in the reference, which are stated to modulate the PPARγ receptor and are stated as useful in the diagnosis and treatment of type II diabetes (and complications thereof) and inflammatory disorders.